Want to know what it's like to be zapped into the brain of a guy who's about to be blown up on a train? You can get your first real taste.

The first four and a half minutes of Duncan Jones' Source Code are online. Witness for yourself Jake Gyllenhaal's confusion at finding himself in the body of another man on a train... and then foom. (You can also watch the film's opening in HD, at Yahoo.)

Plus here are a few more clips:

And here's a new featurette about the film that explains the mysterious technology:

And in case that wasn't enough, Pee-Wee Herman explains Source Code for you:Click to view